An overcharged battery can deteriorate quickly.
Automotive batteries are situate under intense demands, much in every-day driving conditions. Repeated starts, ardent conditions and massive electrical loads all build stresses that batteries must withstand on a common justification. In spite of this, automotive batteries normally wish brief control or preservation, and they normally perform able-bodied for the activity of their lives. Under important circumstances, but, such as when an alternator fails and overcharges the electrical method, batteries can deteriorate quickly, displaying warning signs that a complication exists.
Low electrolyte levels are a symptom signaling that the alternator is overcharging the battery. Electrolyte levels within the battery become low because heat generated from overcharging causes the electrolyte to evaporate. The battery's ability to hold a charge lessens as the electrolyte evaporates, which further accelerates heat buildup and increases the rate of evaporation.
Heating
When a battery becomes overcharged, material sheds from the plates inside and settles to the bottom of the battery casing, causing the plates to lose their ability to hold an electrical charge. This creates resistance to an electrical current, and excess electrical charge is radiated as heat. This causes the battery to feel warm or hot to the touch after the vehicle has been running.
Swelling
An overcharged battery creates excessive amounts of hydrogen gas quickly. This buildup of gas creates pressure inside the battery casing that results in the battery appearing to swell. The normally flat sides and top of the battery will appear somewhat rounded or bulging. In serious cases, the battery can split open or even explode.
